I'm with the grandparent comment.

> But even if a PM cares about UX,

How can a PM do their job if they don't *care* about UX?

I mean... I know exactly happens because I've seen it more than once: the product slowly goes to shit. You get a bunch of PMs at various levels of seniority all pursuing separate goals, not collaborating, not actually working together to compose a coherent product; their production teams are actively encouraged to be siloed; features collide and overlap, or worse conflict; every component redefines what a button looks like; bundles bloat; you have three different rendering tools (ok, I've not seen that in practice but it seems to be encouraged by many "best practices") etc etc

Oh, I agree completely with you, sorry if that wasn't clear. The PM should, must, care about UX. Still, they don't always do, or at least end up not caring eventually, for various reasons.

I'm just responding to this:

> what were your Product Managers doing in the first place if tech writer is finding out about usability problems

They might very well be doing their job of caring about UX, by using the available expertise to find problems.

It's a bit like saying (forgive the imperfect analogy): what are the developers doing talking about corner cases in the business logic, isn't the PM doing their job?

Yes, they are. They are using the combined expertise in the team.

Let's allow the PMs to rely on the knowledge and insights of other people, shall we? Their job already isn't easy, even (or especially) if they care.